Peters



(No Model.)

H. O.HU1V[PHREY.

METHOD OF SETTLING STARGH LI UOR. No. 250,362. Patented Dec. 6,1881.

NVENTOR.

UNITED STATES PATENT OFFICE.

HENRY G. HUMPHREY, ()F NE\V YORK, N. Y.

METHOD OF SETTLING STARCH-LIQUOR.

SPECIFICATION forming part of Letters Patent No. 250,362, dated December6, 1881.

Application filed September 22, 1881. (No model.)

To all whom it may concern:

Be it known that I, HENRY O. HUMPHREY, of the city and State of NewYork, have invented an Improved Method of Settling Starch- Liquor, ofwhich the following is a specification.

In the ordinary method of manufacturing starch, the raw starch-liquor,having a density of, say, 5 Baum, is run over a long trough or so-calledtable, or a succession of tables, upon the bottom of which the starch isdeposited. By far the greater portion of the starch is deposited uponthe first thirty or forty feet of the table; but in order to secure allthe starch it is customary to employ tables of great length, in somecases one hundred and twenty-five or even one hundred and fifty feet inlength, or to run the starch-liquor over a series of tables of shorterlength. In running a distance of sixty feet over a table thestarchliquor is lowered in density from, say, 5 Baume to, say, 1 Baum,and the starch deposited on the lower portion of the table is alwaysless pure than that deposited upon the higher portion of it.

It is the threefold object of my invention to dispense with thenecessity for the use of long tables, and also to increase the purity ofthe starch deposit, and to shorten the operation of depositing thestarch. To thateud Iemploy, in combination with acomparatively shortstarchtable, one or more settling-tanks, into which the overflow fromthe starch-tableis d ischarged, and which, when full, I allow to standfor six hours, more or less, until the heavier materials have settledinto the lower stratum of the liquid contained in the tanks. 1 then drawoff the clear liquor, and thus have remaining a liquor containingsufficient starch to give it a density of, say, 4 or 5 Baum, which Ithen stir up and run over the table. I preferably provide each tablewith two settling-tanks, which are filled alternately by the overflowingstarch-liquor, and the table can thus be continuously employed under themost favorable conditions for obtaining the purest deposit of starch. Bythe use of several settling-tanks ample time is allowed for theconcentration of the raw starch-liquor previously to running it a secondtime over the starch-table.

The apparatus required to carry out my method of collecting the starchis of simple and well-known character, as will be seen from theaccompanying drawings, which represent two starch-troughs provided withtwo settlingtanks.

In these drawings, Figure 1 is a top view, and Fig. 2 is a longitudinalvertical section, of the apparatus.

The trough A is constructed in the usual manner, and for the purpose ofillustrating my invention may be assumed to be sixty feet in length. Theraw-starch liquor is introduced at the upper end, B, into the trough,and as it flows through the trough deposits upon the bottom thereof,say, eighty per cent. of the starch which it originally contained.Assuming it to have had a density of 5 Baum when first introduced intothe upper end of the starch-trough, the liquid overflowing from theopposite end 0 will therefore have a density of, say, 1 Baum. Thisliquid is discharged from the lower end, 0, of the trough upon a chute,D, by which it is conducted either to the settling-tank E or thesettling-tank F, as may be required. As often as there is a sufficientdeposit of starch in the settling-trough the feedingot' the raw-starchliquor is arrested, and the deposited starch is removed from the troughand the feeding of raw-starch liquor recom men ced. When one of thesettling-tanks is full the chute is arranged to conduct the overflowingstarch-liquor to the other settling-tank. The settling-tanks are made ofsufficieut capacity to hold the quantity of starch overflowing from thelower end of the trough during the operation of depositing a charge ofstarch upon the bottom of the trough. After standing six hours, more orless, in the settling-tank, the superincumbent clear liquor is drawn offtherefrom through the pipes c and f, respectively, which in the drawingsare represented as being so placed as to effect the discharge offour-fifths of the contents of either tank. The remaining liquid in thetank, on being stirred by means of the stirrer E, is brought to auniform density, which will be found to he, say, 5Baum. Havingbeenthusstirred,itisdrawn or pumped from the tank and discharged upon thestarch table, where, by reason of its concentration, the starch itcontains is deposited with the usual rapidity.

The necessity of pumping from the settlingtanks may be avoided byproviding the supplemental table G, arranged on a lower level than thebottom of the settling-tanks, so that the concentrated liquid maybe runby its own gravity from the settling-tanks, respectively, through one-0fthe pipes g to the upper end. of the supplemental table G.

I claim as my invention- 1. The herein-described method of separatingstarch from raw-starch liquor, which consists in first running the rawliquor over a comparatively short starch-table, and in collecting andconcentrating the overflow therefrom, and

in then running such concentrated liquor again over a table.

2. In apparatus for separating starch from raw-starch liquor, thestarch-table A, in combination with a settling-tank arranged to receivethe overflow from the table A? and provided with a stirrer, and meansfor reconducting the lower stratum of its contents to astarchtable,substantially as and for the purpose set forth.

H. O. HUMPHREY.

Witnesses:

H. E. NIEsE, R0131. MOELLER.

